Low-cost thermo-electric infrared FPAs and their automotive applications

Abstract

This paper describes three low-cost infrared focal plane arrays (FPAs) having a 1,536, 2,304, and 10,800 elements and experimental vehicle systems. They have a low-cost potential because each element consists of p-n polysilicon thermocouples, which allows the use of low-cost ultra-fine micro-fabrication technology commonly employed in the conventional semiconductor manufacturing processes. To increase the responsivity of FPA, we have developed a precisely patterned Au-black absorber that has high infrared absorptivity of more than 90%. The FPA having a 2,304 elements achieved high resposivity of 4,300 V/W. In order to reduce package cost, we developed a vacuum-sealed package integrated with a molded ZnS lens. The camera aiming the temperature measurement of a passenger cabin is compact and light weight devices that measures 45 × 45 × 30 mm and weighs 190 g. The camera achieves a noise equivalent temperature deviation (NETD) of less than 0.7°C from 0 to 40°C. In this paper, we also present a several experimental systems that use infrared cameras. One experimental system is a blind spot pedestrian warning system that employs four infrared cameras. It can detect the infrared radiation emitted from a human body and alerts the driver when a pedestrian is in a blind spot. The system can also prevent the vehicle from moving in the direction of the pedestrian. Another system uses a visible-light camera and infrared sensors to detect the presence of a pedestrian in a rear blind spot and alerts the driver. The third system is a new type of human-machine interface system that enables the driver to control the car's audio system without letting go of the steering wheel. Uncooled infrared cameras are still costly, which limits their automotive use to high-end luxury cars at present. To promote widespread use of IR imaging sensors on vehicles, we need to reduce their cost further.

Modeling of CMOS Single Membrane Thermopile Detector Arrays

“…I NFRARED (IR) detector Focal Plane Arrays (FPA) are becoming cost-effective devices for high-volume consumer applications [1], [2], including within the Internet of Things (IoT) [3], [4], care services [5] and presence detection for security applications [6]. Compared to other IR detection technologies [7], [8], thermopile-based FPAs can be fabricated more flexibly using standard low-cost complementary metal-oxide-semiconductor (CMOS) processes [9]- [11].…”

Parylene Supported Uncooled Thermoelectric Infrared Detector With Umbrella Like Absorber

“…In this paper, the focus is to improve the sensitivity of the thermoelectric detectors by improving the thermal isolation resistance between the hot and the cold junctions. There have been many efforts dedicated to developing these detectors in the past [3,4,5,6]. This work continues the trend of decreasing the detector size, using folded thermal isolation arms, and introduc the application of a high thermally-resistive polymer (i.e.…”